Various types of antenna structures have been developed to pick-up or to radiate radio-frequency (RF) or other electromagnetic (EM) waves. An antenna system can iv configured to operate in a given antenna bandwidth to meet particular application requirements. Generally, the complexity of designing an appropriate antenna tends to increase when the antenna size as well as other parameters operate to constrain the antenna design.
As one example, a conformal antenna can be constructed and integrated within a vehicle structure, such as an aircraft. The conformal antenna can be implemented as a load bearing or as non-loadbearing structure, for example. More recently, conformal loadbearing structure excitation antennas have been developed for use on tactical aircraft. While such structures can provide an efficient use of the available “real estate” on the aircraft, such existing conformal antennas usually cannot cover all of the communications bands needed for certain applications.
As a further example, modern manned and unmanned tactical aircraft require radio communications over multiple frequency bandwidths. These radio frequency bandwidths generally include the VHF frequency modulation (FM) band (30-88 MHz), the VHF amplitude modulation (AM) band (118-174 MHz) and the UHF band (225-400 MHz). Known antenna systems used on tactical aircraft for Communication Navigation and Identification (CNI) functions have typically included blade antennas that have a fin protruding from the surface of the aircraft. Generally, multiple blade antennas are required for the CNI functions including one for the VHF/FM frequency band, one for the VHF/AM frequency band and another one for the UHF frequency band.
There remains a need for a broadband antenna that can be efficiently packaged for use in tactical aircraft as well as other vehicles or other non-vehicular structures.